Method of forming electrical terminal members



Now-25, 1930. DE HART G. SCRANTOM 1,782,447

METHOD OF FORMING ELECTRICAL TERMINAL MEMBERS Filed June 29. 1927Patented Nov. 25, 1930 UNITED STATES PATENT OFFICE DE HART GRIDLEY SCRANTOM, OF MAPLEWOOD, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY,INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF METHOD OF FORMINGELECTRICAL TERMINAL MEMBERS Application filed June 29,

This invention relates to a method of form ing electricalterminal'members, and more particularly to a method of forming castterminal clips on electrical conductors.

An object of the invention is to providea simple, eflicient andinexpensive method of producing a strong and durable terminal clip on ametallic strand.

In accordance with'one embodiment, the invention contemplates theprovision of a method for integrally securing a terminal member to ametallic strand consisting in casting the terminal member and attachingit to the strand simultaneously. S ecifically, the invention resides ina method For casting terminal clips and affixing them to insulatedelectrical conductors, in which the molten metal is forced against theendof the insulat ed conductor in such a manner as to remove theinsulating material from the tip of the conductor while the metallicstrand 'or strands of the conductor which are more rigid and which donot flare to the same extent become firmly embedded in and form a goodelectrical connection with the terminal mem- It is believed that acomplete understanding of the invention may be had by reference to thefollowing description taken in conjunction with the accompanying drawingillustrating terminal cli s produced by the method and one type of moldor die which may be used in practicing the method, and in which Fig. 1represents a fragmentary, plan View of adie in which the terminal clipsmay be cast;

Fig. 2 is a sectional view 22 of Fig. 1, and

Fig. 3 is an enlarged sectional view showing a stranded conductorembedded in a terminal clip.

Referring to the drawing in which similar reference characters designatethe same parts in the several views, a mold or die 7 of any usual typeemployed in die casting, is'shown taken on the line consisting of anupper section 8 and a lower section 9. The die may be made of any metalsuitable for die or other pressure casting such as steel and eachsection is provided with re- 1927. Serial No. 202,277.

cesses which cooperate with recesses in an opposing section to formcavities 13 into which the terminal members are cast. Between thecavities of each pair a small compression chamber 12 of the usual typeis located which connects with the cavities by means of smalldepressions 16 in the lower die section a few thousandths of an inchdeep for the purpose of allowing the air to escape from the cavities asthey are being filled with molten metal. The cavities 13 are allinterconnected by means of a channel 14 in the lower die member whichleads to an opening 15 through which molten material, suitable for diecasting, such as zinc-magnesium alloy or aluminum and adapted to produceterminals having the requisite physical and electrical characteristicsis forced into the cavities. The sections 8 and 9 are also provided withcooperating grooves forming openings 10 into which the conductors 11which are to be provided with terminal members may be inserted into thecavities 13.

In practicing the method, the insulated conductors to be provided withterminal members, which may comprise a plurality of twisted cotton orother textile cores spirally served with electrically conducting tinselribbon and covered with braided textile sheaths are placed, without theremoval of the insulation therefrom or other preparation, in the groovesin the lower section 8 of the die so as to extend into the cavities 13the desired distance and the upper section 9 is placed in positionfirmly clamping the portions of the conductors in the openings 10. Themolten metal is then forced under pressure into the opening 15 as iswell understood in the art of die casting, from where it follows thechannel 14 leading to the cavities l3, filling them with metal. When themolten metal is forced against the fiat end of the insulated conductor,the ends of the strands of the textile insulating material will unraveland on account of the flexibility of the strands the in-' sulatingmaterial will be flared and moved to a position in which it will becomecompletely embeddedin the material of the terminal. The metallic strandsof the conductor are more rigid and will therefore outwardly not beflared as much as the insulation so that the metal of the terminal clipis cast directly around the strands of the conductor and becomesmolecularly integral with the conductor, producing a good joint from amechanical as well as an electrical standpoint. After the terminal clipshave cooled suflioientl they are removed from the die and trimmed fromthe metal in the channel completing the die casting operation. j It willbe understood that the embodiment ofthe invention herein described andillustrated is merely a convenient and useful form of the invention,which is capable of many other modifications without departing from thespirit and scope of the invention.

\Vhat is claimed is: 1. ,A method of making a terminal member for aninsulated conductor, which comprises forcing a molten metallongitudinally against the end of the insulated conductor to remove theinsulating material therefrom, and formi-ng the metal into a terminalmember contacting with the conductor where the insulation is removed andoverlapping a portion of the insulation.

2; A method of making a terminal clip for a conductor having a strandedtextile insus lation, which comprises forcing a molten 00 metallongitudinally against the end of the conductor and the insulation so asto flare the insulation, and forming the terminal clip over theconductor and the flared insulation.

3. The method of providing a terminal clip on an insulated electricalconductor having flexible strands, which consists in forcing I moltenmetal longitudinally against the end of the conductor, causing the-metalto flare the insulation and the flexible strands, and 40 cooling themetal While confining it in the shape of a terminal clip. In witnesswhereof, I hereunto subscribe my name this 14th day of June, A. D. 1927.DE HART GRIDLEY SGRANTOM.

